| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a display body including a concealed pattern by optical diffraction structure in which the visual discrimination of the pattern is made extremely difficult and a forgery preventing effect is made superior, and to provide its discrimination tool. <P>SOLUTION: The display surface 2 of the display body including the optical diffraction structure is constituted of double structure having stripe pairs 6 of first and second linear stripes 6<SB>1</SB>and 6<SB>2</SB>which are adjacent to each other and parallel with each other and have different diffraction characteristics, and diffraction gratings 7<SB>1</SB>and 7<SB>2</SB>which constitute the linear stripes 6<SB>1</SB>and 6<SB>2</SB>. By making the tilt angles β1 and β2 of the diffraction gratings 7<SB>1</SB>and 7<SB>2</SB>and the tilt angle α of the stripe pair 6 in pattern areas X and Y the same as each other and making the pitches d<SB>1</SB>and d<SB>2</SB>of the stripe pair 6 therein different from each other, it is difficult to discriminate the concealed pattern X or Y in a visually confirming state but the pattern X or Y can be discriminated by superposing the discrimination tool composed of a transparent part and an opaque part having the same pitch as the pitch d<SB>1</SB>or d<SB>2</SB>of the stripe pair 6 of the concealed pattern on the display surface. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
